PROC＋＋批量导入导出ORACLE数据库表

最近在开发一个项目中，为了解决数据库ＩＯ瓶颈，不得不把数据库中的数据导出为文本文件。文本传到客户端后又要导入到数据库。本人用Ｃ＋＋Builder嵌入PROC++写了一个导入导出的DLL。假如对你有用深感荣幸！具体内容如下： 一、预备工作计算机环境：Win 2000 PRO,Oracle 9i,C++ Builder 5.5引入必要的ORACLE内部函数：要用的函数在$(ORACEL_HOME)bin qlora9.dll链接库中。为了能在C++ Builder中使用，先得生成LIB：implib sqlora9.lib sqlora9.dll二、源文件分析//-------------------------------------------------------------------------//加入必要的头文件#include<vcl.h> #include<windows.h> #include<stdio.h> #include<stdlib.h> #include<string.h>#include<time.h> #include<math.h> #include<fcntl.h> #include<io.h> #include<sys tat.h>//说明DLL的输出函数extern 'C' _declspec(dlleXPort) int _stdcall ConnectDB(const char *Username, const char *PassWord, const char *Dbname);extern 'C' _declspec(dllexport) int _stdcall ImportTxtfile(TList *LengthArray, String *FieldArray, const char *TableName, const char *FileName);extern 'C' _declspec(dllexport) int _stdcall ExportTxtfile(const char *Sql, const char *FileName); #pragma hdrstop//----------------------------------------------------------------------------#define MAX_ITEMS 20;;;;;//定义最大字段数#define MAX_VNAME_LEN 30; //定义选择表项最大长度#define MAX_INAME_LEN 30; //定义指示器变量名字的最大长度EXEC SQL INCLUDE sqlca;;//说明SQL通讯区EXEC SQL INCLUDE oraca;;//说明ORACLE通讯区EXEC SQL INCLUDE sqlda;;//说明SQL语句描述结构/*SQLDA结构体请查相关资料*/EXEC ORACLE OPTION (ORACA = YES);EXEC ORACLE OPTION (RELEASE_CURSOR = YES);//说明ORACLE外部函数extern 'C' _declspec(dllimport) void _stdcall sqlclu(SQLDA*);extern 'C' _declspec(dllimport) void _stdcall sqlnul(short*, short*, int*);extern 'C' _declspec(dllimport) void _stdcall sqlprc(int*, int*, int*);extern 'C' _declspec(dllimport) strUCt SQLDA * _stdcall sqlald(int, unsigned int, unsigned int);SQLDA *SelectUnit//定义选择项描述SQLDA *BindUnit//定义输入项空间//定义变量，以存放连接数据库的参数EXEC SQL BEGIN DECLARE SECTION; char User[20];//用户名 char Pwd[20];//密码 char DB[20];//数据库服务名EXEC SQL END DECLARE SECTION;bool bConnect = false;//是否连接标志#pragma hdrstop#pragma argsused//C++ Builder DLL的主函数BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fwdreason, LPVOID lpvReserved){ ;;return 1;}/*--------------------------------------------------------------------------- 连接数据库---------------------------------------------------------------------------*/int _stdcall ConnectDB(const char *Username, const char *Password, ;;;const char *Dbname){ strcpy(User, Username); strcpy(Pwd, Password); strcpy(DB, Dbname); EXEC SQL CONNECT :User IDENTIFIED BY :Pwd USING :DB; if (sqlca.sqlcode < 0) return -1; bConnect = true; return 0;}/*---------------------------------------------------------------------------导出文本函数因为不确定SELECT语句的表及字段，所以我使用动态语句(ORACLE DYNAMIC SQL)的//第四种方式。 动态SQL方法四是在不确定SQL语句的选择项与输入项，且不知个数与数据类型的情况下使用的一种复杂程序设计技术。---------------------------------------------------------------------------*/int _stdcall ExportTxtfile(const char *Sql/*SQL选择语句*/, const char FileName/*导出目标文本文件名*/){ int null_ok, precision, scale; int handle; if ((handle = open(FileName, O_CREATO_TEXTO_APPENDO_RDWR, S_IREADS_IWRITE)) == -1) { //文件打开出错 return -1; }//定义变量，以存放SQL语句 EXEC SQL BEGIN DECLARE SECTION; char sqlstr[256]; EXEC SQL END DECLARE SECTION; //检查是否连接数据库 if (bConnect == false) return -2; strcpy(sqlstr/*.arr*/, Sql); //; sqlstr.len = strlen(sql); //给描述区分配空间; if ((SelectUnit = sqlald(MAX_ITEMS, MAX_VNAME_LEN, MAX_INAME_LEN)) == (SQLDA *)NULL) { //空间分配失败 return -3; } if ((BindUnit = sqlald(MAX_ITEMS, MAX_VNAME_LEN, MAX_INAME_LEN)) == (SQLDA *)NULL) { //空间分配失败 return -3; } //给查询返回值存储区分配空间 SelectUnit->N = MAX_ITEMS; for (int i=0; i < MAX_ITEMS; i++) { BindUnit->I[i] = (short *)malloc(sizeof(short *)); BindUnit->V[i] = (char *)malloc(MAX_VNAME_LEN); } for (int i=0; i < MAX_ITEMS; i++) { SelectUnit->I[i] = (short *)malloc(sizeof(short *)); SelectUnit->V[i] = (char *)malloc(MAX_VNAME_LEN); } EXEC SQL WHENEVER SQLERROR GOTO sqlerr;//DO sql_error('导出出错');//设置ＳＱＬ语句 EXEC SQL PREPARE SQLSA FROM :sqlstr; EXEC SQL DECLARE Cursorbase CURSOR FOR SQLSA; //输入描述处理 BindUnit->N = MAX_ITEMS; EXEC SQL DESCRIBE BIND VARIABLES for SQLSA INTO BindUnit; if (BindUnit->F < 0) { return -4; //输入项过多 } BindUnit->N = BindUnit->F; //打开光标 EXEC SQL OPEN Cursorbase USING DESCRIPTOR BindUnit; //选择项处理 EXEC SQL DESCRIBE SELECT LIST for SQLSA INTO SelectUnit; if (SelectUnit->F < 0) { return -4; //选择表项过多 } SelectUnit->N = SelectUnit->F;//因为所有格式，类型都是不确定的，所以要得到正确的返回值就要处理格式 for (int i=0; i < SelectUnit->F; i++) { sqlnul(&(SelectUnit->T[i]), &(SelectUnit->T[i]), &null_ok); switch (SelectUnit->T[i]) { ;;;;case 1://CHAR ;;;;;;;;;break; ;;;;case 2://NUMBER ;;;;;;;;;sqlprc(&(SelectUnit->L[i]), &precision, &scale); ;;;;;;;;;if (precision == 0) ;;;;;;;;;;;precision = 40; ;;;;;;;;;SelectUnit->L[i] = precision + 2; ;;;;;;;;;break; case 8://LONG ;;;SelectUnit->L[i] = 240; break; case 11://ROWID SelectUnit->L[i] = 18; break; case 12://DATE SelectUnit->L[i] = 9; break; case 23://RAW break; case 24://LONGRAW SelectUnit->L[i] = 240; break; } SelectUnit->V[i] = (char *)realloc(SelectUnit->V[i], SelectUnit->L[i]+1); SelectUnit->T[i] = 1;//把所有类型转换为字符型 } EXEC SQL WHENEVER NOT FOUND goto EndFor; for (;;) { EXEC SQL FETCH Cursorbase USING DESCRIPTOR SelectUnit; //输出各字段 for (int i=0; i < SelectUnit->F; i++) { char buffer[256]; if (i != SelectUnit->F-1) sprintf(buffer, '%s', SelectUnit->V[i]); else sprintf(buffer, '%srn', SelectUnit->V[i]); int length = strlen(buffer); if (write(handle, buffer, length) != length) { return -5; //写文件失败 exit(1); } } }EndFor: close(handle); for (int i=0; i < MAX_ITEMS; i++) { if (SelectUnit->V[i] != (char *)NULL) free(SelectUnit->V[i]); free(SelectUnit->I[i]); } for (int j=0; j < MAX_ITEMS; j++) { if (BindUnit->V[j] != (char *)NULL) free(BindUnit->V[j]); free(BindUnit->I[j]); } sqlclu(SelectUnit); sqlclu(BindUnit); EXEC SQL CLOSE Cursorbase; return 0;sqlerr: return -6;}/*----------------------------------------------------------------------------导入文本为了批量导入，在此我调用的sqlldr工具首先生成SQL*Loader控制文件，后运行sqlldr----------------------------------------------------------------------------*/int _stdcall ImportTxtfile(TList LengthArray/*导入文本的字段长度链表*/,String *FieldArray/*数据库表的了段名数组*/, const char TableName/*导入的目标表*/, const char FileName/*导入的源文本文件*/){ //产生SQL*Loader控制文件 FILE *fout, *fp; char Execommand[256]; char sqlload[] = '. qlload.ctl'; //检查是否连接数据库 if (bConnect == false) return -2; if ((fout=fopen(sqlload, 'w')) == NULL) { //建立控制文件出错 return -1 ; } fprintf(fout, 'LOAD DATAn'); fprintf(fout, 'INFILE '%s'n', FileName); fprintf(fout, 'APPEND INTO TABLE %s (n', TableName); int iStart = 1; for(int i=0; i < LengthArray->Count; i++) { fprintf(fout, '%11s POSITION(%d:%d)', FieldArray[i], iStart, *(int*)LengthArray->Items[i]+iStart-1); iStart += *(int*)LengthArray->Items[i]; fprintf(fout, ' CHAR'); if(i < LengthArray->Count-1) fprintf(fout, ',n'); } fprintf(fout, ')n'); fclose(fout); sprintf(Execommand, 'sqlldr.exe userid=%s/%s@%s control=%s', User, Pwd, DB, sqlload); if (system(Execommand) == -1) { //SQL*Loader执行错误 return -1; } return 0 ;}//----------------------------------------------------------------------------三、编译用ORACLE的PROC预编译器预编后，放入C++ Builder中联编。 联编时需加入前面生成的sqlora9.lib。联编时还要注重，所有PROC生成的ORACLE内部函数调用都要说明为extern 'C' _declspec(dllexport) TYPE _stdcall类型。水平有限还请见谅！！！请多多指点。ＱＱ：5005647